Please show all work and what functions are used in a TI-84 plus calculator.

8. If there are 9 cyclists in a race, how many ways can the gold, silver, and bronze be awarded if there are no ties? (2 points) 9. In order to conduct an experiment, 4 subjects are randomly selected from a pool of 20. How many different groups are possible? (2 points) 10. The monthly utility bills in a city are normally distributed with a mean of $100 and a standard deviation of $12. (2 points each) a) Find the probability that a bill is less than $70. b) Find the probability that a bill is between $90 and $120. c) Find the probability that a bill is more than $119. d) If 4 bills are selected at random, what is the probability that the mean amount is more than $105? e) Which of the above events are unusual, if any? Explain